Johnson 4HP Gummed Gearset?

[way2fst4u]

I have a 197x? Johnson 4HP outboard. In Neutral (with the motor off), I'm finding it very difficult to spin the prop by hand. If I start it, in neutral, it revs right up...no problem. In gear, on the water, I can only get about 1/2 throttle (any higher and it doesn't rev higher). The boat never planes. I'm running this on a small 10ft pontoon bass boat (Pelican Bass Raider). I get maybe 5mph at best. I've changed the gear oil, and it made no difference. The oil that came out was not milky.

Any help is appreciated!
Thanks!

Scott

 

[Chinewalker]

Re: Johnson 4HP Gummed Gearset?

Your motor sounds like it's more likely from the 1980s, when they started adding a neutral clutch to the 4hp models. Spinning the prop in neutral will still give you drag on the prop as the neutral requires the motor running to release the tension on the clutch spring.

A 4hp won't plane a 10-ft pontoon, not matter how well it's running. Has it ever run well for you? .ie, is it running differently than before? It's possible the motor is only running on one cylinder. Check for spark and compression...

 

[way2fst4u]

Re: Johnson 4HP Gummed Gearset?

Your motor sounds like it's more likely from the 1980s, when they started adding a neutral clutch to the 4hp models. Spinning the prop in neutral will still give you drag on the prop as the neutral requires the motor running to release the tension on the clutch spring.

A 4hp won't plane a 10-ft pontoon, not matter how well it's running. Has it ever run well for you? .ie, is it running differently than before? It's possible the motor is only running on one cylinder. Check for spark and compression...

I just got the motor from a neighbor. it was sitting in a basement for 8 yrs. I know several people with the same motor. Planes the boat no problem...hits about 10-12mph...I get left behind. I guess it could be running on one cyl...? I'm going to change plugs and see. Can I start it and run it without water in neutral? Even just for a minute or two?

 

[Chinewalker]

Re: Johnson 4HP Gummed Gearset?

Can I start it and run it without water in neutral? Even just for a minute or two?

Absolutely not! Fill a trash can if you need to just to get the unit in the water. Fill up above the seam between the exhaust leg and the unit to get the pump submerged - they're not self-priming...

While you have the plugs out, check for spark...